California officials expect that the state needs 1 gigawatt of new long-duration energy storage by 2026 to advance its clean-energy transition.
That figure emerged in the “reference system portfolio” that the California Public Utilities Commission approved on March 26. The grid planning document calls for no new gas plants, although almost all of the existing capacity is expected to remain online throughout the decade. But it adds 11 gigawatts of utility-scale solar by 2030, nearly 3 gigawatts of wind and a groundbreaking amount of energy storage.
The plan anticipates 8,873 megawatts of batteries, the technology that dominates the energy storage market today. That’s many times over the national cumulative installed battery capacity that’s now installed. But the CPUC broke new ground in carving out space for the addition of nearly 1 gigawatt of “pumped storage, or other long-duration storage with similar attributes” by 2026.
“This is the first formal mechanism we’ve seen that recognizes that need in the system,” said Mateo Jaramillo, co-founder of seasonal storage technology startup Form Energy. “The state recognizes that it needs to send the right signal to the market now in order to meet the longer-term goals.”
Technologists working on long-duration storage, which proposes to complement wind and solar plants by storing power for many more hours than lithium-ion batteries can handle cost-effectively, have raised hundreds of millions of venture dollars and grant funding and produced an eclectic mix of plausible technologies. But none of them have achieved enduring success in the electricity markets as constituted today.
With the official call for 1 gigawatt of new long-duration capacity, California could become the first clear market for some of these emerging technologies, or perhaps the return of the oldest: pumped hydro storage. Then again, the CPUC planning document alone lacks the power to make that happen.
How big a deal is this?
Long-duration storage is not new to California. The CPUC already oversees 1,600 megawatts of pumped hydro storage. Those decades-old projects play a vital role in the state’s water supply system as well as serving the grid.